This invention relates to a disposable sanitary article such as a disposable diaper, incontinence pants or training pants and a process for attaching elastic members associated with leg-openings to such a sanitary article.
Japanese Patent Application Publication No. 1992-317650A describes a process for attaching elastic members associated with leg-openings to a sanitary article comprising steps of forming a continuous sheet along its transversely opposite side edge portions with longitudinally continuous adhesive zones, forcibly guiding a plurality of the elastic members associated with the leg-openings to extend under tension across the continuous sheet transversely thereof and bonding them to the continuous sheet in a pattern of sine curves. The elastic members associated with the leg-openings attached to the article by the process disclosed in the Publication present a stretch stress identical in front and rear waist regions except a middle zone of a crotch region.
With the sanitary article in the form of the pull-on type diaper particularly for baby, the diaper is apt to leave a space between the baby's skin and the diaper in a front half of the crotch region due to a brisk movement of the baby. In view of this, the stretch stress of the elastic members associated with the leg-openings is preferably preadjusted to be higher in the front half than in the rear half of the crotch region. With the sanitary article in the form of the open-type diaper, in order to avoid an anxiety that the front waist region of the diaper might slip down during use of the diaper, to facilitate the diaper to be put on the baby's body and to provide a good fit of the diaper to the baby's body, the stretch stress of the elastic members associated with the leg-openings is preferably preadjusted to be higher on the front half of the crotch region provided with a target tape strip than on the rear half of the crotch region provided with a pair of tape fasteners. However, the elastic members associated with the leg-openings attached by the process disclosed in the Publication present a substantially identical stretch stress between the front and rear halves of the crotch region. Such feature does not make the elastic members associated with the leg-openings to have the functions required by both the pull-on type diaper and the open type diaper.